1. Field of the Invention
This invention relates generally to a miniature motor, and more particularly to a miniature motor being adapted to suppress spark generation between a plurality of commutator segments and brushes by connecting a resistors to each of the commutator segments.
2. Description of the Prior Art
Miniature motors having a spark-quenching means to suppress spark generation between a plurality of commutator segments and brushes by connecting resistors to each of the commutator segments are generally known.
A well-known arrangement for quenching sparks between the commutator segments and the brushes is to utilize a ring resistor in which thick-film resistors as many as the rotor poles are disposed on a ring-shaped printed circuit board with the adjoining thick-film resistors being connected with copper foil, for example; the copper foil being soldered to the commutator segments. With this arrangement, however, soldering is required to connect the ring resistor to the commutator segments, resulting in increased manufacturing cost in addition to the expensive ring resistor.
Another conventional spark-quenching arrangement is to connect rotor windings to commutator terminals provided integrally with the commutator segments, and then adhere a short cylindrical electrically conductive rubber by an electrically conductive adhesive so as to cover the commutator terminals. This arrangement also involves an unwanted problem of an electrically conductive adhesive required to adhere the ring-shaped electrically conductive rubber to the commutator.